Hello Friend,
I think your best option in this case is for you to postpone your exam for a few more weeks and do all you can to practice on the ITTO's if you are preparing for the CAPM Exams. On the hand if you targeting to write the PMP Exam then knowing more about EV formulas will benefit you significantly. I already have CAPM but it is expiring in August so I am preparing to re-write this Exam again and I know for a fact that if you are going to write the CAPM Exam then it almost a must that you know the in and out of the ITTO's I was originally going to write the Exam in June but has Postpone it till Mid July as I am brushing up on the ITTO's